code: def __init__(
      self, client_count=None, host_is_alive=True, dead_job_queue=None
  ):
      self.last_heartbeat_time = time.time()
      self.last_heartbeat_table = dict()
      self.exit_flag = False
      self.client_count = client_count
      self.dead_job_queue = dead_job_queue
      self.host_is_alive = host_is_alive
      self.host_pid = None
  
imports: import grpc
  import os
  import time
  import threading
  from concurrent import futures
  from parl.remote import remote_constants
  from parl.remote.grpc_heartbeat import heartbeat_pb2
  from parl.remote.grpc_heartbeat import heartbeat_pb2_grpc
  from parl.utils import logger, get_ip_address
  import psutil
  import multiprocessing
label_desc: Use image node_id 1 to create a new GrpcHeartbeatServer object from inherited base classes: heartbeat_pb2_grpc with example: obj = GrpcHeartbeatServer(client_count, host_is_alive, dead_job_queue)